Most lead actors with American movie careers have simple goals: They want to be noble, trusted, adored and successful forever.

Put as simply as that, you may detect a gap between acting and life. And in life, you never quite know about people. You have to stay alert, and make up your own mind.

That is why for about 10 years Robert De Niro was so different and so important. He played lead roles, but he was unfixed and not just unpredictable, but dangerous.

Before De Niro, Cagney had that mercurial closeness to outrage. Yet we guessed Cagney’s heart was in the right place — unless he was doing a flat-out villain, like Cody Jarrett in “White Heat.” And villains are different. Richard Widmark was fearsome for a moment in the late ’40s, until his own good nature or his agent got to him, and he turned sour but decent, and rather duller.

Related

De Niro played leads, protagonists and halfway heroes, but he was never more disturbing than when that razor smile sliced his face. Of course, De Niro was blessed by sharing in the great years of Martin Scorsese, but I’m not sure any other actor could have done “Mean Streets,” “Taxi Driver,” “New York, New York” or “Raging Bull” with his intimidating ambiguity.

Very often in our movies, no matter the extremes to which a character goes, you feel the inescapable ordinariness or conservatism or amiability of an actor’s personality. That reassuring base is there in Olivier, in Jack Nicholson, in Jean-Paul Belmondo. It’s in their eyes and the way they look at people. They think the world is spoiled, but OK.

I can think of only a few people in whom that reassurance is absent — Alain Delon, perhaps, Robert Mitchum certainly. Mitchum was largely disenchanted with acting, and he never had a Scorsese to drive him.

But it wasn’t only with Scorsese that De Niro seemed alien: Brando’s Vito Corleone is a sad gangster and a sadder father; De Niro’s young Vito was a guy of Asperger’s like distance, yet as poised as a knife held in a pocket. He had been out of his mind in “Bloody Mama,” a couple of years before “Mean Streets,” and in time he would make Michael in “The Deer Hunter” a Dostoyevskyan lone wolf.

By contrast, even with Kazan at his side, he was utterly stranded trying to play Monroe Stahr in “The Last Tycoon.” Stahr is a mastermind, but a guy with a soft heart, a lost love and a wish to do well by the world, and De Niro seemed to have no understanding of such sentiments. Then and now, he has never seemed to grasp love stories.

So he was great for the best part of 10 years. “Taxi Driver” and “Raging Bull” are the obvious examples. My favorite is “New York, New York,” where the story and a yearning Liza Minnelli do their best to persuade themselves and us that he might just be likeable, sweet and a good dad.

He wasn’t, and we owe that revelation plenty. By contrast, today’s young actors look desperate and compromised by their endless search for respect and affection.

De Niro didn’t care about us, and it altered movies.

David Thomson is the author of more than 20 books, including “The New Biographical Dictionary of Film.”

Sign Up for Daily Insider Newsletter

Most lead actors with American movie careers have simple goals: They want to be noble, trusted, adored and successful forever. Put as simply as that, you may detect a gap between acting and life. And in life, you never quite know about people. You have to stay alert, and make up your own mind. That […]

Most lead actors with American movie careers have simple goals: They want to be noble, trusted, adored and successful forever. Put as simply as that, you may detect a gap between acting and life. And in life, you never quite know about people. You have to stay alert, and make up your own mind. That […]

Most lead actors with American movie careers have simple goals: They want to be noble, trusted, adored and successful forever. Put as simply as that, you may detect a gap between acting and life. And in life, you never quite know about people. You have to stay alert, and make up your own mind. That […]

Most lead actors with American movie careers have simple goals: They want to be noble, trusted, adored and successful forever. Put as simply as that, you may detect a gap between acting and life. And in life, you never quite know about people. You have to stay alert, and make up your own mind. That […]

Most lead actors with American movie careers have simple goals: They want to be noble, trusted, adored and successful forever. Put as simply as that, you may detect a gap between acting and life. And in life, you never quite know about people. You have to stay alert, and make up your own mind. That […]

Most lead actors with American movie careers have simple goals: They want to be noble, trusted, adored and successful forever. Put as simply as that, you may detect a gap between acting and life. And in life, you never quite know about people. You have to stay alert, and make up your own mind. That […]

Most lead actors with American movie careers have simple goals: They want to be noble, trusted, adored and successful forever. Put as simply as that, you may detect a gap between acting and life. And in life, you never quite know about people. You have to stay alert, and make up your own mind. That […]